The present invention relates to a closing device for closing a filling opening of a coke oven chamber. More particularly, the present invention relates to such a closing device of the type including a frame positioned on the coke oven and a cover adapted to be inserted into the frame.
It is known to close the filling openings of coke oven chambers by closing devices including a frame fitting on the coke oven chamber ceiling such that an opening through the frame aligns with the filling opening of the coke oven chamber ceiling, and a filling cover adapted to be inserted into the frame to close the opening, the frame and cover having complementary sealing surfaces which operate to close and seal the filling opening. However, during the normal use of a coke oven chamber, such known frames and covers are exposed to very high thermal loads. This causes differential expansion between the frame and the cover, such that it is not possible to attain sufficient sealing tightness of the cover during the entire coking phase or operation of the coke oven chamber. Tar-containing crude gases will escape at positions of leaks between the sealing surfaces of the frame and the cover. Such gases are condensed during the cooling which takes place during discharge of the coke oven chamber, and the resultant solid residues become deposited on the sealing surfaces of the cover and frame, thereby further preventing the achievement of a tight seal. Such residues can be removed only with very great difficulty.